The expression of growth hormone(GH) and insulin-like growth factor I(IGF-I) receptor mRNAs in brain tumors, and tumor proliferation.The relationship between the expression of GH receptor (GH-R) and IGF-I receptor (IGF-I R)mRNAs, and tumor proliferation has not been elucidated in human brain tumors. We investigated the expression of these receptors in 22 cases of astrocytic tumor and 20 cases of meningioma using not only reverse transcription-PCR(RT-PCR) but also immunohistochemical technique. In 22 case of astrocytic tumor, 11 cases were low grade astrocytoma and the rest were high grade one. Using RT-PCR,GH-R mRNA was found in 95% of meningiomas and in 86.4% of astrocytic trumors. IGF-I-R mRNA was found in 80% of meningiomas and in 91.0% of astrocytic tumors. GH-R and IGF-I-R mRNA in astrocytic tumors were expressed not only in high grade astrocytomas but also in low grade astrocytomas. Statistically, there were no significant relationship between the expression of these mRNAs and hi
… Morestological grade. In immunohistochemical study using frozen tissue, the distribution of IGF-I-R was diffusely recognized in the cytoplasm of meningioma cells and astrocytic tumor cells. On the other hand, IGF-I-R could not be detected in the tumor cells using paraffin embedded tissue. These results demonstrated the existence of IGF-I-R and GH-R in human astrocytic tumors and meningiomas. These receptors may play a role in the tumor cell proliferation and growth, and it is possible that not only IGF-I-R but also GH itself are one of growth accelerating factors in astrocytic tumors and meningiomas.We are now investigating the distribution of GH-R and IGF-I-R mRNAs in brain tumors using in site hybridization technique.・アイソジェン(Takara)にてmRNAを抽出し、reverse transcriptase(RAV-2,Takara)を用いてcDNAを作製したのち、Taq polymerase(Takara)にてPCRを行った。・cycleの条件は35cycle;denature 94℃ 30 s.annealing 55℃ 30 s.extension 72℃ 60sに統一したが、3種類のprimerともに良好な結果が得られた(GeneAmp PCR System 2400,PERKIN ELMER)。結果:・house keeping geneである32M mRNAの発現により保存状態が良好と確認された標本に於いて、髄膜腫20例中19例にGH-RのmRNAの発現を認め、16例にIGF-1-RのmRNAの発現を認めた。神経膠腫(良性11例、悪性11例)22例中19例にGH-RのmRNAの発現を認め、20例にIGF-1-RのmRNAの発現を認めた。・神経膠腫の悪性度とGH-R、IGH-1-RmRNAの発現には、有意差は見られなかった。・今後の課題として、悪性度との相関の判定には、競合的PCRなどによる定量化が必要と考えられた。2.IGF-1-Rに対する抗体(CALBIOCHEM社)を使用し、ABC法による免疫染色で同タンパクの発現を検索した。結果:既存のホルマリン同定、ハラフィン包理の標本では、染色は不可能であった。OCT compound包理後に-80℃保存したsampleを4%PFAにて固定、薄切したものは染色良好で髄膜腫では胞体に明らかな陽性像を得た。神経膠腫も胞体に陽性像を認めている。現在、良好なsampleを集積中である。 Less